However, I’ve also configured postscreen in my Postfix instance. Most of the spambots are rejected by postscreen and thus never reach the mail server. Still, since every spambot will easily make 10 to 15 attempts, and every attempt creates quite a bit of log noise. I’d like to reject them quickly so they’re not polluting my logs, and this is where fail2ban becomes a useful ally. Since there was no available fail2ban filter for postscreen, I wrote one myself, along with the corresponding config/activation file – both suffixed .local so as not to interfere with future upgrades.